An R-T-B based sintered magnet containing a rare earth element R, a transition metal element T such as Fe or Co, and boron B exhibits excellent magnetic properties. Hitherto, a number of investigations have been carried out in order to improve the residual magnetic flux density (Br) and coercive force (HcJ) of an R-T-B based sintered magnet. For example, it is known that the coercive force and the rectangularity in the magnetization curve are improved by setting the amount of the rare earth element in a metal state contained in the magnet base material to a predetermined amount or more (Patent Literature 1).